1. Field Of The Invention
The invention relates to alignment apparatus, and more particularly, to a system for establishing the axial alignment of a first rotatably mounted shaft (extending from a first unit) with respect to a second rotatably mounted shaft extending from a second unit, where the shafts are arranged in an end-to-end orientation.
2. Background And Objects Of The Invention
There is a known need in the art to properly align the shaft of a first torque producing unit with the shaft of a second loading (component) unit. The desired axial alignment, if true and precise, provides for the high efficiency coupling of torque from the first unit to the second unit. Often the shafts are associated with respective rotating members of the each unit. The misalignment of the shafts may provide an angular alignment error where the center-lines of the two shafts intersect at an angle, or may be manifested by a parallel offset misalignment error where the respective shafts are parallel but exhibit an axial offset with the center-lines of each shaft not concentrically or coaxially aligned. Of course, a combination of angular and parallel offset misalignments are certainly possible. If the units are not properly aligned, where the respective shafts are not axially aligned along a common center-line or axis, the result may be damage to various components including items such as bearings, seals, gears, couplings, and the like. In addition, energy lost via friction and "vibration" may be conserved with proper axial alignment and delivered to the load.
A variety of "alignment fixtures" are known in the art to assist in the accurate alignment (or alignment verification) of coupled or uncoupled (but soon to be coupled) shafts. For example, an apparatus which may be employed to determine the alignment accuracy of two shafts is provided by U.S. pat. No. 4,553,335 to Woyton. The Woyton apparatus provides for readings (alignment information) to be provided either by well known means such as dial indicators or linear variable differential transformer (LVDT) transducers, which are particularly useful for providing alignment information to a calculating or computing device to determine the amount of "shimming" which is required to properly axially align the respective shafts. Another known device, as provided by U.S. Pat. No. 5.056,237 to Saunders, may be employed with either coupled or uncoupled shafts to determine the alignment status thereof. The Saunders invention is arrangable for providing electronic alignment information (as well as dial indications). However, with each of the above alignment arrangements, and others available in the art, there exists a need to manually adjust the height of one or more units being aligned by using shims, and the like. In addition, many commonly employed alignment means and methods require relatively large amounts of time to produce a satisfactory alignment result.
Common shaft alignment methods are well know to skilled persons. For example, one commonly used method for determining alignment information, and one which is contemplated for use by Woyton and Saunders, is the well known "reverse indicator" or "reverse alignment" method. The reverse alignment process involves collecting alignment information at four (specific) locations having a 90 degree rotational displacement, as well known to said skilled persons. Again, these methods are generally employed to gather and determine the amount of shimming or spacing necessary to align a first shaft with respect to a second coupled, or to be coupled, shaft.
The advent of low cost computing and control components, including but not limited to microprocessors, microcontrollers, programmable logic controllers (PLCs) and programmable logic devices, has resulted in many computer based systems being designed for a large variety of functions and applications. These systems, which are often termed embedded (computer) systems, provide for the full or partial automation of many known processes or procedures, which have in the past been carried out manually or in a non-automated manner. For example, there is a need in the art for an improved alignment system which will support the automated and rapid alignment of a first shaft with respect to a second (possibly loading) shaft. Such systems may be designed using many known off-the-shelf components that may be applied to "automate" and or simplify many manually conducted alignment methods, which are presently employed in the art.
Objects of the present invention are, therefore, to provide new and improved precision shaft alignment systems having one or more of the following capabilities, features, and/or characteristics:
enables quick and easy axial alignment of two rotatably mounted opposed shafts; PA1 computer controlled manual (via operator input) or automated axial alignment processes supported; PA1 portable system; PA1 modular, simple, and flexible system architecture; PA1 significantly reduces the setup, calibration and alignment times typically required (when compared to many known alignment systems); PA1 very simple methods to realize precision alignment; PA1 includes low profile vertical actuator unit assemblies and embodiments; PA1 employs many common off-the-shelf components and devices.
The above listed objects, advantages, and associated novel features of the present invention, as well as others, will become more clear from the description and figures provided herein. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the invention, limited only by the scope of the appended claims.